Article-wrapping machines are usually provided with a rotating knife which severs a continuous web to form wrappers therefrom to enwrap articles. In the majority of the presently-used wrapping machines, when an article to be wrapped is absent, the knife and web-feeding unit are stopped to discontinue the production of wrappers. This discontinuance requires the installation, in the kinematic chain which actuates the knife and web-feeding unit, of a dog clutch capable of timely re-activating said unit and the knife connected thereto.
Due to the high operating speed of the modern wrapping machines, the dogs of this clutch experience considerable mechanical stress during re-activation step, with the disadvantages resulting from this condition.